Abstract: The Iris database management system is a research prototype being developed at Hewlett-Packard Laboratories. Its goals are to enhance database programmer productivity and to provide generalized database support for the integration of future applications. Iris is based on an object and function model. Iris objects are typed, but, unlike other object systems, Iris objects contain no state. Attribute values, relationships and behavior of objects are modeled by functions. The Iris architecture efficiently supports the evaluation of functional expressions. The goal of the architecture is to provide a database system that is powerful enough to support the definition of functions and procedures that implement the semantics of the data model. This paper provides an overview of the data model, describes the architecture in detail and discusses our implementation experience and usage of the system.